For sensing stress applied to a member having elasticity, a method for adhering a strain gauge is commonly well known. For monitoring a stress (tensile stress and compressive stress) applied to around-foot members of an automobile and the like, however, robust property is required. Therefore, the method for using the strain gauge has a problem.
A non-patent document Garshelis, Ivan J., “New types of Magnetoelastic Transducers for Sensing Force Related Parameters,” “SAE Paper,” No. 910856, “Sensors and Actuator,” 1991 proposes a stress sensor utilizing a reverse effect of magnetostriction (magnetostrictive stress sensor).